Mojo::Client::basic.pm

sub build_tx {
    my ($self, $user, $pass)  = @_;
    croak("Basic authorization user name can't contain ':'")
        if $user =~ /:/;


		               # or build_tx('POST|GET|...', ...), see Mojo::Client
    my ($tx, $cb)  = $self->client->build_form_tx($url, {
      field => 'value', 
      # ...

    });

    $tx->req->headers->header(
        Authorization => 'Basic ' . b($self->user . ':' . $self->pass)->b64_encode
    );

    return $tx;
}